COMMON FRACTIONAL DISPERSION - MANAGED ANTIREFLECTION COATINGS FOR SECOND AND HIGHER HARMONICS GENERATION

摘要

Any designed two-layer antireflection coating with calculated phase thicknesses z and y of the first and second matching layers, respectively, always allows the following "looking-glass" transformation: z → 2π - z, y → 2π - y. In each of such solutions one of the layers is always thicker (and another thiner) than quarter-wavelength. It is shown in Fig.1. The duality of solutions was exploited earlier for design of the integral multiple layers antireflection coatings transparent for two selected wavelengths λ_1 and λ_2. Here we report application of such dual-band antireflection coatings for design of laser windows for second and higher harmonic generation, i.e. when the scaling parameter y= λ_2/λ_1 should be selected as an integer as in case of the harmonic generations.